Image forming apparatuses such as printers, facsimiles, copiers, and multi-function machines having the functions of a printer, a facsimile, and a copier, form images by conveying a medium (hereinafter also referred to as “paper”) and jetting a liquid (hereinafter also referred to as “recording liquid” or “ink”) onto the medium. In forming the images, the image forming apparatus uses, for example, a liquid jet apparatus including a recording head having a liquid jet head for jetting droplets of liquid (recording liquid). It is to be noted that image forming may also be referred to as recording, printing, image printing, or character printing. It is also to be noted that the material of the medium is not limited to a particular material. Thus, the medium may be also be referred to as a target recording medium, a recording medium, transfer material, or a recording paper.
The image forming may be performed on a medium made of, for example, paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, or ceramic. Furthermore, the image forming not only includes forming images which have meaning (e.g., characters, shapes) but also includes forming images having no particular meaning (e.g., patterns). Furthermore, as long as images can be formed, the liquid is not limited to a recording liquid or ink. The liquid jet apparatus refers to an apparatus that jets liquid by using a liquid jet head.
One example of the liquid jet head used in the above-described liquid jet apparatus of the image forming apparatus is disclosed in Japanese Laid-Open Patent Application No. 3-286870 (hereinafter referred to as “Patent Document 1”). The liquid jet head disclosed in Patent Document 1 has a nozzle member and a flow path member that are bonded together as different members by using a thermal diffusion method.
Japanese Laid-Open Patent Application Nos. 10-16215, 2000-218792, and 11-179908 (hereinafter referred to as “Patent Document 2”, “Patent Document 3”, and “Patent Document 4”, respectively) disclose a liquid jet head having a nozzle member and a flow path member integrally formed by using an electroforming method (electrocrystallization).
As another example of the liquid jet head, Japanese Laid-Open Patent Application No. 9-300635 (hereinafter referred to as “Patent Document 5”) discloses a liquid jet head using a method of forming a vibration plate (diaphragm) by Ni electroforming and fabricating the crystal lattice planes (111) and (100) of an Ni crystalline member to satisfy a relationship (111)≧(100). As another of the liquid jet heads, Japanese Laid-Open Patent Application No. 8-142334 (hereinafter referred to as “Patent Document 6”) discloses a liquid jet head using a method of forming a nozzle member by Ni electroforming.
However, in a case of bonding together different members (i.e. nozzle member and flow path member) such as in Patent Document 1, the thinness of the nozzle member causes difficulty in handling and makes the nozzle member susceptible to deformation by electrocrystallization stress. Thus, it is difficult to bond large areas together. Furthermore, the processes of positioning and diffusion bonding are complicated. Inaccurate positioning between a nozzle and a liquid chamber leads to problems such as an undesired liquid jetting direction (e.g., liquid droplet deviating from target).
Particularly, under the circumstance where there is a growing demand for a liquid jet head capable of forming dots (dpi, dots per inch) with high density, it is becoming more difficult to perform bonding by using an adhesive agent. That is, it is almost impossible to steadily apply an adhesive agent in the bonding process. Even if an adhesive agent can be applied, it is difficult to achieve sufficient bonding strength.
The method of integrally forming the nozzle member and the flow path member by electroforming (such as in Patent Document 2) can resolve the difficulty of bonding the nozzle member and the flow path member. However, this method does not take into consideration, for example, rigidity or strength of the members, processing time of the members, or surface characteristics of the members related to liquid fluidity (flow characteristics).
For example, in order to reduce the fluid resistance (flow resistance) of the nozzle member, it is suitable to form the inlet of the nozzle member into a round shape. Furthermore, fine protrusions or recesses or foreign matter formed on the inner wall of the nozzle member cause inconsistency (fluctuation) in the formation of a meniscus. This leads to deviation of the liquid jetting direction. Furthermore, the nozzle member is required to have sufficient rigidity against external force for preventing deformation (e.g., vibration or deformation by pressure during liquid jetting or by contact with a medium). Moreover, the flow path member is required to have sufficient rigidity for enduring liquid pressure for efficiently changing the pressure in a liquid chamber.
However, since the method of integrally forming the nozzle member and the flow path member does not consider rigidity or strength of the members, processing time of the members, or surface characteristics of the members related to liquid fluidity (flow characteristics), the method is unable to provide sufficiently stable liquid jetting efficiency and liquid jetting performance.
In addition, there is also a method of integrally forming a flow path member and a fluid resistance member having a fluid resistance part provided between a liquid chamber and a common flow path for supplying liquid to each liquid chamber (the fluid resistance part having greater fluid resistance than the liquid chamber), a method of integrally forming a flow path member and a filter member having a filter part extending from a common flow path to a liquid chamber for catching foreign matter, or a method of integrally forming a flow path member and a vibration plate member. Nevertheless, in the case of integrally forming the flow path member and a thin member (material that is thinner than the flow path member such as the nozzle member, the fluid resistance member, the filter member, the vibration plate member), it is difficult to attain sufficient rigidity for the thin member.